Fuel blending preheater vaporizer



8- 27, 1940- R. w. WARRICK I 2,213,154

FUEL BLENDING PREHEATER VAPORIZER Filed Jan. 9, 1940 Patented Aug. 27, 1940 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to fuel supply devices and more particularly to pre-heating manifolds for internal combustion engines.

Although this invention may be applied to twocylinder engines, it is equally usable in connection with multiple cylinder engines. In the operation of internal combustion engines it is acknowledged that gasoline is an expensive fuel and that less expensive fuels are desirable, such as low cost oils. Diesel engines are capable of using such relatively inexpensive fuels, but there is generally present the inherent difficulty of starting such engines. The present invention is especially adapted for use in connection with engines wherein a high cost fuel such as gasoline may be used for initially starting the engine, and in which the Operation is quickly shifted .to the use of oil as the fuel for continuous operation. It is desirable to pre-heat all fuel and air mixtures coming into the cylinders, but numerous problems are presented.

Applicant has designed a highly efficient fuel pre-heating device comprising this inventive concept.

One object of this invention is to provide an improved heating manifold for oil burning engines.

Another object is to provide a more efficient utilization of exhaust heat in an internal combustion engine.

Still another object is to provide heated fuel intake arranged to minimize the counter-cooling effect of the engine walls.

Yet a further object is to provide a pre-heating construction utilizing heat of exhaust gases by means of conducting structures.

Other objects and advantages of this invention will appear from the following description taken in connection with the accompanying drawing.

In the drawing, wherein like reference characters indicate corresponding parts in the various figures;

Figure 1 is a partial vertical cross-section indicating the application of this inventive concept to a two-cylinder tractor engine.

Figure 2 is a horizontal cross-section taken substantially on the line 2--2 of Figure 1, and illustrating a section through the heating manifold.

Figure 3 is an enlarged detail View of the preheating portion of the fuel inlet pipe.

Figure 4 is a cross-section taken along the line 4--4 of Figure 1.

Considering the drawing in greater detail, one cylinder I0 of an engine is indicated having a piston I2 arranged to reciprocate therein and connected by a. crank rod l4 through suitable gearing, clutches, etc. (not shown) to the driving wheels of a tractor or other vehicle. A portion of the cooling system is shown comprising the hollow cylinder block l6 surrounding the cylinder or cylinders and connected to a water pipe 18 coming from a radiator, and to pipe 20 returning the heated cooling medium to the radiator for further cooling. An air breather and ventilator 22 is connected to the crank case of the engine and one rocker arm 24 is shown to operate the fuel inlet valve 26. A fuel intake pipe 28 is connected to the exhaust manifold 3!]. Appropriate internal connections transform the cool incoming supply of fuel into a pre-heated fuel supply which can be supplied to the engine through the intake ports 32.

A cylinder head 34 is bolted to the cylinder block in an appropriate manner and contains.

water passages 36 in communication with the passages IS in the cylinder block which serve to maintain the cylinder head at some appropriate temperature and to eliminate excessive heat. A

passage 38 in the casting forming the cylinder head connects the inlet port 32 of the cylinder to the fuel outlet 40 of the exhaust manifold 30.

The exhaust manifold is arranged to be secured to the cylinder head casting by appropriate fastening means at 42. The fuel supply pipe 28 is secured to the exhaust manifold and is placed in communication with a relatively thin metal tube 44, which extends through the exhaust manifold and carries the fuel part way through the manifold. A solid metal shell 46 extends at rightangles to the tube 44 and is secured in the exhaust manifold at right angles to the tube. This is clearly seen in the various figures, so that the fuel going to the engine cylinders comes from pipe 28 through pipe 44 and into the transversely extending metal shell 46 by way of opening 48. The engine is generally arranged with the intake ports extending through the cylinder head between the exhaust ports 50 and 52, as observed in Figure 2. The exhaust ports 50 and 52 are in direct communication with the exhaust passages of the cylinder head, and the exhaust pipe 54 carries the exhaust gases from the manifold to the muffler or other desirable point on the engine.

With the usual manifold arrangement, relatively great inefficiencies occur, and it is one of the objects of this invention to arrange the preheating structure to avoid this difficulty. The central cylinder 46 is so positioned in the path between the exhaust port 50 of the exhaust manifold and the exhaust outlet 54 thereof so that a streamline flow of hot exhaust gases continually passes from one cylinder about the fuel inlet elements and thence through the exhaust port 54 to the atmosphere. The exhaust manifold is provided with an angularly directed wall portion 56, arranged with respect to the exhaust port 52 and the exhaust pipe 54, whereby to direct the exhaust gases from the engine entering port 52 against the fuel pipe parts 44 and 46 before the flow of these exhaust gases pass out of the manifold by way of the exhaust pipe 54. In this manner, the fuel supply is heated at all times by a continuous flow of hot exhaust gases coming from at least two cylinders of the engine. More effective vaporization of fuel is accomplished in this manner, and avoidance of condensation of fuel is also accomplished.

The fuel heater has its outer wall 58 composed of two metal discs 59 and 60, between which is interposed an asbestos disc 6|. These three discs effectively close the outer end 63 of a fuel tube 62 which carries the heated fuel to the inlet port.

The fuel tube 62 extends through the fuel supply pipe 38 of the cylinder head. The supply pipe has a surrounding body of water or other cooling medium and is consequently relatively cool with respect to the temperature of the incoming fuel. If the fuel tube and pipe are in close metal contact, condensation of fuel can take place with a consequent loss of efficiency of combustion. It is contemplated by the present invention that the fuel supply tube 62 shall be of relatively smooth metal finish, attained by any appropriate commercial process. The inner walls of the passage 38 being parts of a casting are relatively rough. As viewed in Figure 3, it will be observed that the metal to metal contact between the fuel tube 62 and the fuel pipe 38 is relatively very small, as indicated at 64. This removes the water-cooling effect from the incoming fuel. Engine efiiciencies are increased and condensation of fuel is eliminated by means of this arrangement of parts.

Furthermore, the fuel tube 62, being of relatively smooth metal in comparison with the surfaces of passage 38, additionally reduces any skin effect orretardation of fuel flow in the tube. This also enhances the flow of fuel to the engine, reducing the surface friction and assisting in avoidance of condensation on the walls of the tube.

The fuel tube 62 is also provided with an annular flange 66, either integrally formed thereon or connected thereto by very close metal to metal contact, which serves to close the end of the cylinder 46. Spaced lugs 68 and 1D utilize only a portion of the space between the cylinder 46 and the tube 62, but are arranged with arcuate outer surfaces for engagement with the inner walls of the cylinder 46. A bafile wall 1'2 is similarly constructed, but in this instance the wall completely divides the annular passage into two arcuate paths M and 16, by means of which fuel flows around in thermal contact with the outer walls 46 and the inner tube walls 62, striking against the bafile l2 and entering the tube by means of slotted passages or ports 18.

The arrangement of. the heater as described places the outerwall of the metal cylinder 46 in direct contact with the exhaust gases from the engine at all times, whereas the tube 62, by means of the heat conducting lugs 68, '10 and I2, is also heated by conduction at all times. This creates a very efficient heat transfer by allowing the fuel to flow between relatively narrowly spaced heated surfaces.

It will be readily understood that the structure heretofore described is capable of providing a very highly efficient pre-heating of fuel for an engine, along with simplification in structure, economy in fuel, reduction in exhaust temperatures, avoidance of condensation, and other economies herein described.

Although a preferred embodiment of this invention is illustrated and described, variations within the true spirit and scope of the same are to be determined by the appended claims.

What I claim is:

1. A fuel blending preheater vaporizer comprising a cast metal structure forming a vaporized fuel conducting passage, and a smooth walled vaporized fuel conducting metal tube positioned to extend at least partially through said passage, and to have metal to metal contact with said passage over a relatively small portion of the possible co-extensive contact areas of the tube and passage.

2. A fuel blending preheater vaporizer comprising a metal cylinder head having a fuel conducting passage therein, a metal exhaust manifold arranged for cooperation with said cylinder head, and a manifold core forming a circuitous fuel heating passage through said manifold and cylinder head and defined by spaced walls, with one of said walls arranged to be heated by contact with the out-flowing exhaust gases and the other wall being heated by conduction from said first named wall and an extension from said conduction heating wall comprising a smooth walled vaporized fuel conducting metal tube positioned to extend at least partially through said fuel conducting passage, and to have metal to metal contact with said passage over a relatively small portion of the possible co-extensive contact areas of said tube and passage.

3. A fuel blending preheating vaporizer for a multi-cylinder internal combustion engine comprising a cylinder head having a fuel conducting passage therein, an exhaust manifold arranged for cooperation with said cylinder head, a manifold core defined by spaced walls forming a fuel heating passage through said manifold and cylinder head, and a plurality of ports in said manifold arranged for communication with the exhaust ports of the cylinders and having an outlet therefor, said manifold arranged to effect continuous thermal contact between the exhaust gases from all of said cylinders and said core.

4. A fuel blending preheater vaporizer for an internal combustion engine, comprising an exhaust manifold adapted for securement to said engine, a fuel passage extending through said manifold and into said engine, and a manifold core arranged to constitute the portion of said passage in said manifold, said core comprising spaced heat conducting walls forming an annular passage, and heat conducting bosses interconnecting said walls, whereby the heating of the outer wall by the passage of exhaust gases through the manifold effects a heating of the inner wall.

5. A fuel vaporizer comprising an exhaust gas manifold, a fuel inlet conduit extending into said manifold, a metal cylinder in communication with said conduit forming a fuel receiving housing in said manifold, and an apertured fuel tube extending through said metal cylinder and forming therewith dual arcuate passages for heating said fuel.

6. A fuel vaporizer comprising, in combination With an exhaust manifold having a fuel inlet conduit extending thereinto, a vaporizing core in said manifold comprising a discharge tube, and inner and outer shells on said tube, in thermal metallic continuity with one another and with said tube, the outer shell being exposed to the hot exhaust gas in said manifold, said inner and outer shells forming between them a vaporizing chamber into which said fuel inlet conduit opens through said outer shell, the inner shell having an opening communicating with said fuel discharge tube on the side of said inner shell opposite the opening of said inlet conduit.

RAY W. WARRICK. 

